I used the trip planner on the website, which is awesome. I downloaded the app hoping to do the same, so I can monitor it while on my trip. However, on the app I can only find local prices, I can't chart out a route like I can do on the website. It would be a great feature to allow this, and if you really want to get fancy, to link it with google's navigation on the droid phones, so you can get turn-by-turn directions WITH fuel stops.

You can access the full Gas Buddy website using your mobile device's browser.

Realize that the prices for the "fuel stops" are only as good as members such as you and me posting prices for gas stations. Prices don't magically appear or become available because of Gas Buddy; prices appear because members post them and update them so they're current for the benefit of other members (just as other members do for us).